US5399269A - Gelation of water soluble polymers - Google Patents

Gelation of water soluble polymers Download PDF

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US5399269A
US5399269A US08/220,140 US22014094A US5399269A US 5399269 A US5399269 A US 5399269A US 22014094 A US22014094 A US 22014094A US 5399269 A US5399269 A US 5399269A
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Ahmad Moradi-Araghi
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ConocoPhillips Co
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    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K8/00Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
    • C09K8/50Compositions for plastering borehole walls, i.e. compositions for temporary consolidation of borehole walls
    • C09K8/504Compositions based on water or polar solvents
    • C09K8/506Compositions based on water or polar solvents containing organic compounds
    • C09K8/508Compositions based on water or polar solvents containing organic compounds macromolecular compounds
    • C09K8/512Compositions based on water or polar solvents containing organic compounds macromolecular compounds containing cross-linking agents
    • CCHEMISTRY; METALLURGY
    • C08ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08KUse of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K5/00Use of organic ingredients
    • C08K5/0008Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
    • C08K5/0025Crosslinking or vulcanising agents; including accelerators
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S507/00Earth boring, well treating, and oil field chemistry
    • Y10S507/903Crosslinked resin or polymer

Definitions

  • the present invention relates to gelation of water soluble polymers by organic crosslinking agents and to a gelable composition that increases the gel strength of the gelled water soluble polymers.
  • gelled water soluble polymers are useful in enhanced oil recovery operations. They have been used to alter the permeability of underground formations in order to enhance the effectiveness of water flooding operations.
  • the polymers along with an appropriate crosslinking agent are injected in an aqueous solution into the formation. They percolate into and gel in the regions having the highest water permeability. Any fluids injected into the formation in subsequent flooding operations will then be diverted away from the gels into regions of the formation having a lower water permeability.
  • a water-dispersible phenolic compound and a water-dispersible aldehyde have been used together as crosslinking agents for the gelation of water soluble polymers in enhanced oil recovery operations.
  • U.S. Pat. No. 4,799,548 discloses using a phenolic compound and an aldehyde for the formation of gelled water soluble polymers.
  • the water soluble polymers gel fairly quickly, together with these compounds, after being injected into the formation. Quite often only the regions near the well bore are treated because the polymers gel before they have an opportunity to permeate throughout the entire formation.
  • the polymers form gels that do not withstand the reservoirs' high temperature and high salinity environment over a long period of time to effectively alter the permeability of the underground formations.
  • These gelled polymers are exposed to numerous mechanical forces within the formation which tend to promote the breakdown of the gels. When the gels break down, oil production decreases and it is necessary to retreat the formation with more water soluble polymers.
  • the present invention has the advantage of using environmentally substantially less toxic crosslinking agents.
  • a gelable composition which comprises: (1) a water dispersible first crosslinking compound selected from the group consisting of aspirin, p-aminosalicylic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" where Ar represents a phenyl group which can be non-substituted or substituted; R is a hydrogen or a carboxylic group; R' is a C 1 -C 6 alkyl; R" is a hydrogen, a phenyl group, or a C 1 -C 6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) a water dispersible second crosslinking compound selected from the group consisting of aldehydes and aldehyde-generating compounds; (3) a water soluble acrylamide-containing polymer; and (4) water
  • a process for reducing the permeability of a water-out or oil-depleted zones in high temperature subterranean formation comprises injecting a gelable composition comprising: (1) a water dispersible first crosslinking compound selected from the group consisting of aspirin, p-aminosalicylic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" where Ar represents a phenyl group which can be non-substituted or substituted; R is a hydrogen or a carboxylic group; R' is a C 1 -C 6 alkyl; R" is a hydrogen, a phenyl group, or a C 1 -C 6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) a water dispersible second crosslinking compound selected from the group
  • the first crosslinking compound useful for the present invention is water dispersible and is selected from the group consisting of aspirin, p-aminobenzoic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" where Ar is a phenyl group which can be non-substituted or substituted; R is a hydrogen or a carboxylic group; R' is a C 1 -C 6 alkyl; and R" is a hydrogen, a phenyl group or a C 1 -C 6 alkyl.
  • water dispersible used herein is to describe a component of the composition that is truly water soluble or is dispersible in water to form a stable suspension.
  • Suitable first crosslinking compounds include, but not limited to, p-aminosalicylic acid, furfuryl alcohol, phenyl acetate, phenyl propionate, phenyl butyrate, salicylic acid, phenyl salicylate, aspirin, p-hydroxybenzoic acid, methyl p-hydroxybenzoate, methyl o-hydroxybenzoate, ethyl p-hydroxybenzoate, o-hydroxybenzoic acid, hexyl p-hydroxybenzoate, and mixtures thereof.
  • Presently preferred water dispersible first crosslinking compounds are phenyl acetate, phenyl salicylate, salicylic acid, ⁇ -aminobenzoic acid and methyl ⁇ -hydroxybenzoate.
  • any water dispersible aldehyde, its derivative, or compound that can be converted into aldehyde can be utilized as the second crosslinking compound in the present invention.
  • suitable second crosslinking compounds can be selected from the group consisting of aliphatic monoaldehydes, aromatic monoaldehydes, aliphatic dialdehydes, aromatic dialdehydes, and their derivatives.
  • Preferred aldehydes and their derivatives can be selected from the group consisting of formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, decanal, glutaraldehyde, terephthaldehyde, hexamethylenetetramine, and mixtures thereof.
  • the water dispersible first crosslinking compound is present in the composition in the range of from about 0.005 to about 5.0 weight percent, preferably from about 0.01 to about 2.0 weight percent, and most preferably from 0.03 to 1.0 weight percent based on the total weight of the composition.
  • the second crosslinking compound is present in the composition in the range of from about 0.005 to about 5.0 weight percent, preferably from about 0.01 to about 2.0 weight percent, and most preferably from 0.03 to 1.0 weight percent.
  • water soluble acrylamide-containing polymer refers to those polymers which are homopolymers, copolymers, or terpolymers, and are truly water soluble or those which are dispersible in water or other aqueous medium to form a colloidal suspension which can be pumped into a formation and gelled therein.
  • the water soluble acrylamide-containing polymers which are suitable for use in the present invention include those which contain from 5 to 100 mole percent of at least one monomer of the formula: ##STR1## wherein R 1 , R 2 , and R 3 are selected from the group consisting of hydrogen or alkyl groups containing from 1 to 3 carbon atoms, of which acrylamide and methacrylamide are the preferred examples; and from 0 to 95 mole percent of at least one monomer selected from the group consisting of; (a) those monomers represented by the formula: ##STR2## wherein R 4 is selected from the group consisting of hydrogen or alkyl radicals containing from 1 to 6 carbon atoms, R 5 is selected from the group consisting of alkylene radicals containing from 1 to 6 carbon atoms or an arylene radical containing from 6 to 10 carbon atoms, and M is selected from the groups consisting of hydrogen, ammonium, potassium, or sodium, of which 2-acrylamido-2-methylpropane sulfonic acid or sodium 2-acryl
  • the molecular weight of the water soluble acrylamide-containing polymers utilized in the present invention is not critical. It is presently preferred, however, that the polymer have a molecular weight of at least about 100,000 and more preferably 100,000 to 20,000,000. The upper limit is not critical as long as the polymer is still water dispersible and can be pumped into the formation.
  • the presently preferred class of water soluble acrylamide-containing polymers are those selected from the group consisting of homopolymers of acrylamide, homopolymers of methacrylamide, copolymers of acrylamide and acrylic acid, copolymers of acrylamide and potassium acrylate, copolymers of acrylamide and sodium acrylate, copolymers of acrylamide and N,N-dimethylacrylamide, copolymers of acrylamide and methacrylamide, copolymers of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, copolymers of acrylamide and N-vinyl-2-pyrrolidone, terpolymers of acrylamide, N,N-dimethylacrylamide and 2-acrylamido-2-methylpropane sulfonate, and terpolymers of acrylamide, N-vinyl-2-pyrrolidone, and sodium 2-acrylamido-2-methylpropane sulfonate.
  • other polymers with more subunits may also be utilized in the practice of this invention.
  • homopolymers, copolymers, terpolymers, and tetrapolymers utilizing the above listed monomers are particularly preferred.
  • the water soluble acrylamide-containing polymer is present in the composition in the amount of from about 0.05 to about 10 weight percent, preferably from about 0.1 to about 5 weight percent, and most preferably from 0.2 to 4 weight percent.
  • concentration of polymer in the composition depends to some degree upon the molecular weight of the polymer. A high molecular weight results in a higher viscosity of the resulting gel for a particular concentration of polymer.
  • any suitable method can be employed for preparing the composition of the invention.
  • any suitable mixing technique or order of addition of the components of the composition to each other can be employed.
  • the polymer be dispersed in water before contacting the polymer with the other components.
  • the mixing order can vary with the type of polymer used.
  • gelled polymers to alter the water permeability of underground formations is well known to those skilled in the art.
  • an aqueous solution containing the polymer and a crosslinking agent is pumped into the formation so that it can diffuse into the more water permeable portions of the formation and alter that water permeability by gelling therein.
  • the present invention can be used in a similar manner.
  • An aqueous solution containing the water soluble acrylamide-containing polymer, aldehyde compound, and aromatic compound can be pumped into the formation so that it alters the water permeability of the formation in a similar manner when gelation takes place.
  • the present invention's advantage lies in the fact that, since the gelation of the polymer is delayed, the polymer has an opportunity to travel farther into the formation and effect the water permeability of portions of the formation that would normally go untreated due to their distance from the injection site. In addition, the resulting gel exhibits improved strength.
  • composition of the present invention can be used in or can be injected into, fresh water, salt water, or brines, as well as at a temperature range of from about 70° F. to about 400° F., preferably from about 150° F. to about 350° F., and most preferably from 200° F. to 300° F.
  • the purpose of this example is to illustrate the gelation of a water-soluble polymer by phenol and formaldehyde and to use this example as a control.
  • a 0.7 percent solution of a terpolymer composed of 30 wt % of N-vinyl-2-pyrrolidone, 15 wt % of acrylamide, and 55 wt % of sodium 2-acrylamido-2-methylpropane sulfonate was prepared by mixing 11.3 ml of an inverse emulsion which contained 32.4 wt % of the active terpolymer with 500 ml of synthetic sea water.
  • the synthetic sea water used has the following formula:
  • Table I shows that after 1535 days at 200° F. in the presence of 2,000 ppm each of phenol and formaldehyde, relatively poor gel (based on the gel length of 18.2 cm and the liquid height of 0.4 cm) developed. The higher the liquid, the more syneresis was. Syneresis is an undesirable characteristics. Similarly, at 5,000 ppm concentration each of phenol and formaldehyde, faster gelation occurred and shorter gels were formed.
  • Table I also shows that, at higher temperature (250° F.) and at a given crosslinker concentration (2,000 ppm), the gelation rate increased resulting in decreased tongue length indicating improved gel strength. However, when the temperature was 300° F., excessive syneresis was observed in as short as 63 days (1.0 cm liquid) and then at 1109 days, the gel gave 4.0 cm of liquid indicating a severe syneresis.
  • Table II shows that the gels produced with HMTA and phenol as crosslinkers are very comparable in quality to those made with phenol-formaldehyde crosslinking system at equal concentrations and temperatures.
  • Table III show that substantially stronger (i.e. shorter tongue lengths) gels were obtained, when compared with the results of Table I or II.
  • Table III also shows that the composition containing 2,000 ppm each of methyl p-hydroxybenzoate and hexamethylenetetramine did not form strong (short tongue length) gels until after aging for over 550 days at 200° F. or over 71 days at 250° F. However, the results show that some syneresis occurred at 300° F.
  • Table III further demonstrate that HMTA and methyl p-hydroxybenzoate are effective crosslinking agents suitable for high temperature application to form strong gels and to delay gelling.
  • This example shows that excellent gels are formed by a composition containing an acrylamide-containing polymer, phenyl acetate and formaldehyde.
  • Table IV shows that strong gels were formed with the inventive composition, even at very low (1,000 ppm) concentration of crosslinkers. For example, a 100% gel (i.e. 0.0 tongue length) was formed after over 20 days of aging at 250° F.
  • This example illustrates an inventive gelable composition
  • an acrylamide-containing terpolymer, salicylic acid and HMTA forms strong gels.
  • inventive gelable composition comprising an acrylamide-containing terpolymer and proper crosslinking compounds also form strong gels.
  • Example II The runs were carried out the same as those described in Example I except that the crosslinkers and their concentrations in Example I were replaced by those shown in Tables VI-X.
  • Tables VI-X some of the inventive compositions did not gel until after the compositions had been aged at high temperatures for months and eventually formed strong (short tongue length) gels, especially those comprising phenyl acetate and HMTA (Table VIII), and phenyl salicylate and HMTA (Table X), at 250° F., formed gels having 0 cm tongue length.
  • This example illustrates that glyoxal, a formaldehyde precursor that release formaldehyde upon heating, is not a suitable crosslinking agent.
  • hexamethylenetetramine is probably converted to formaldehyde and ammonia upon heating.
  • the in-situ produced formaldehyde is then coupled with a crosslinking agent to form gels with an acrylamide-containing polymer.
  • glyoxal or trioxane which is also converted to formaldehyde upon heating, does not form suitable gels with a crosslinking agent and an acrylamide-containing polymer (Tables XI and XIII-XVI).

Abstract

A gelable composition and process are disclosed that delay the gelation and increase the gel strength of gelled water soluble acrylamide-containing polymers contains: (1) a water dispersible first crosslinking compound selected from the group consisting of p-aminosalicylic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" wherein Ar represents a phenyl group which can be substituted or non-substituted; R is a hydrogen or a carboxylic group; R' is a C1 -C6 alkyl; R" is a hydrogen, a phenyl group, or a C1 -C6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) a water dispersible second crosslinking compound selected from the group consisting of aldehydes and aldehyde-generating compounds; (3) a water soluble acrylamide-containing polymer; and (4) water.

Description

This application is a continuation-in-part of application Ser. No. 07/867,635, filed Apr. 13, 1992 now abandoned.
FIELD OF THE INVENTION
The present invention relates to gelation of water soluble polymers by organic crosslinking agents and to a gelable composition that increases the gel strength of the gelled water soluble polymers.
BACKGROUND OF THE INVENTION
It is well known to those skilled in the art that gelled water soluble polymers are useful in enhanced oil recovery operations. They have been used to alter the permeability of underground formations in order to enhance the effectiveness of water flooding operations.
The polymers along with an appropriate crosslinking agent are injected in an aqueous solution into the formation. They percolate into and gel in the regions having the highest water permeability. Any fluids injected into the formation in subsequent flooding operations will then be diverted away from the gels into regions of the formation having a lower water permeability.
A water-dispersible phenolic compound and a water-dispersible aldehyde have been used together as crosslinking agents for the gelation of water soluble polymers in enhanced oil recovery operations. For example, U.S. Pat. No. 4,799,548 discloses using a phenolic compound and an aldehyde for the formation of gelled water soluble polymers. However, the water soluble polymers gel fairly quickly, together with these compounds, after being injected into the formation. Quite often only the regions near the well bore are treated because the polymers gel before they have an opportunity to permeate throughout the entire formation. Furthermore, the polymers form gels that do not withstand the reservoirs' high temperature and high salinity environment over a long period of time to effectively alter the permeability of the underground formations. These gelled polymers are exposed to numerous mechanical forces within the formation which tend to promote the breakdown of the gels. When the gels break down, oil production decreases and it is necessary to retreat the formation with more water soluble polymers.
It would therefore be a significant contribution to the art to have a composition that would delay the rate of gelation of the water soluble polymers and a process that would increase the gel strength of water soluble polymers.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a composition for delaying the rate at which water soluble polymers are gelled by organic crosslinking agents. It is also an object of the present invention to provide a composition having increased gel strength of the water soluble polymer gels. It is a further object of the present invention to provide a gel composition of water soluble polymers that can withstand high temperature over a long period of time.
The present invention has the advantage of using environmentally substantially less toxic crosslinking agents. Other objects, features, advantages and aspects of the present invention will become apparent as the invention is more fully described in the following disclosure and claims.
According to the present invention, a gelable composition is provided which comprises: (1) a water dispersible first crosslinking compound selected from the group consisting of aspirin, p-aminosalicylic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" where Ar represents a phenyl group which can be non-substituted or substituted; R is a hydrogen or a carboxylic group; R' is a C1 -C6 alkyl; R" is a hydrogen, a phenyl group, or a C1 -C6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) a water dispersible second crosslinking compound selected from the group consisting of aldehydes and aldehyde-generating compounds; (3) a water soluble acrylamide-containing polymer; and (4) water.
According to another embodiment of the present invention, a process for reducing the permeability of a water-out or oil-depleted zones in high temperature subterranean formation comprises injecting a gelable composition comprising: (1) a water dispersible first crosslinking compound selected from the group consisting of aspirin, p-aminosalicylic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" where Ar represents a phenyl group which can be non-substituted or substituted; R is a hydrogen or a carboxylic group; R' is a C1 -C6 alkyl; R" is a hydrogen, a phenyl group, or a C1 -C6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) a water dispersible second crosslinking compound selected from the group consisting of aldehydes and aldehyde-generating compounds; (3) a water soluble acrylamide-containing polymer; and (4) water; into the formation and the gelable composition forms a gel in the formation.
DETAILED DESCRIPTION OF THE INVENTION
The first crosslinking compound useful for the present invention is water dispersible and is selected from the group consisting of aspirin, p-aminobenzoic acid, furfuryl alcohol, RArOC(O)R' and HOArC(O)OR" where Ar is a phenyl group which can be non-substituted or substituted; R is a hydrogen or a carboxylic group; R' is a C1 -C6 alkyl; and R" is a hydrogen, a phenyl group or a C1 -C6 alkyl. The term "water dispersible" used herein is to describe a component of the composition that is truly water soluble or is dispersible in water to form a stable suspension. Suitable first crosslinking compounds include, but not limited to, p-aminosalicylic acid, furfuryl alcohol, phenyl acetate, phenyl propionate, phenyl butyrate, salicylic acid, phenyl salicylate, aspirin, p-hydroxybenzoic acid, methyl p-hydroxybenzoate, methyl o-hydroxybenzoate, ethyl p-hydroxybenzoate, o-hydroxybenzoic acid, hexyl p-hydroxybenzoate, and mixtures thereof. Presently preferred water dispersible first crosslinking compounds are phenyl acetate, phenyl salicylate, salicylic acid, ρ-aminobenzoic acid and methyl ρ-hydroxybenzoate.
Any water dispersible aldehyde, its derivative, or compound that can be converted into aldehyde can be utilized as the second crosslinking compound in the present invention. Thus, suitable second crosslinking compounds can be selected from the group consisting of aliphatic monoaldehydes, aromatic monoaldehydes, aliphatic dialdehydes, aromatic dialdehydes, and their derivatives. Preferred aldehydes and their derivatives can be selected from the group consisting of formaldehyde, paraformaldehyde, acetaldehyde, propionaldehyde, decanal, glutaraldehyde, terephthaldehyde, hexamethylenetetramine, and mixtures thereof.
The water dispersible first crosslinking compound is present in the composition in the range of from about 0.005 to about 5.0 weight percent, preferably from about 0.01 to about 2.0 weight percent, and most preferably from 0.03 to 1.0 weight percent based on the total weight of the composition. The second crosslinking compound is present in the composition in the range of from about 0.005 to about 5.0 weight percent, preferably from about 0.01 to about 2.0 weight percent, and most preferably from 0.03 to 1.0 weight percent.
As used in this application, the term "water soluble acrylamide-containing polymer" refers to those polymers which are homopolymers, copolymers, or terpolymers, and are truly water soluble or those which are dispersible in water or other aqueous medium to form a colloidal suspension which can be pumped into a formation and gelled therein.
The water soluble acrylamide-containing polymers which are suitable for use in the present invention include those which contain from 5 to 100 mole percent of at least one monomer of the formula: ##STR1## wherein R1, R2, and R3 are selected from the group consisting of hydrogen or alkyl groups containing from 1 to 3 carbon atoms, of which acrylamide and methacrylamide are the preferred examples; and from 0 to 95 mole percent of at least one monomer selected from the group consisting of; (a) those monomers represented by the formula: ##STR2## wherein R4 is selected from the group consisting of hydrogen or alkyl radicals containing from 1 to 6 carbon atoms, R5 is selected from the group consisting of alkylene radicals containing from 1 to 6 carbon atoms or an arylene radical containing from 6 to 10 carbon atoms, and M is selected from the groups consisting of hydrogen, ammonium, potassium, or sodium, of which 2-acrylamido-2-methylpropane sulfonic acid or sodium 2-acrylamide-2-methylpropane sulfonate are the preferred examples; or (b) monomers represented by the formula: ##STR3## where R6, R7 and R8 are independently selected from the group consisting of hydrogen or alkyl groups containing from 1 to 2 carbon atoms of which N-vinyl-2-pyrrolidone is the preferred example; or (c) at least one monomer selected from the group consisting of acrylic acid, sodium acrylate, potassium acrylate, ammonium acrylate, methacrylic acid, sodium methacrylate, potassium methacrylate, ammonium methacrylate, vinylsulfonic acid, sodium vinylsulfonate, potassium vinylsulfonate, ammonium vinylsulfonate, vinylbenzylsulfonic acid, N,N-dimethylacrylamide, sodium vinylbenzylsulfonate, potassium vinylbenzylsulfonate, vinylacetate, acrylonitrile, methacrylonitrile, vinyl alkyl ether, vinyl chloride, maleic anhydride, vinyl substituted cationic quaternary ammonium compounds, (acryloyloxy-ethyl)diethylmethylammonium methyl sulfate; or (d) mixtures thereof.
The polymerization of any of the above described monomers and their resulting polymers are well known to those skilled in the art. There are numerous references which disclose methods of polymerizing these monomers. For example, See U.S. Pat. No. 4,244,826.
The manner in which these monomers are polymerized into water soluble acrylamide-containing polymers or the resulting polymer is not critical to the practice of the present invention. Polymerization can be initiated by chemicals, irradiation, or any other techniques known to those skilled in the art.
The molecular weight of the water soluble acrylamide-containing polymers utilized in the present invention is not critical. It is presently preferred, however, that the polymer have a molecular weight of at least about 100,000 and more preferably 100,000 to 20,000,000. The upper limit is not critical as long as the polymer is still water dispersible and can be pumped into the formation.
The presently preferred class of water soluble acrylamide-containing polymers are those selected from the group consisting of homopolymers of acrylamide, homopolymers of methacrylamide, copolymers of acrylamide and acrylic acid, copolymers of acrylamide and potassium acrylate, copolymers of acrylamide and sodium acrylate, copolymers of acrylamide and N,N-dimethylacrylamide, copolymers of acrylamide and methacrylamide, copolymers of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, copolymers of acrylamide and N-vinyl-2-pyrrolidone, terpolymers of acrylamide, N,N-dimethylacrylamide and 2-acrylamido-2-methylpropane sulfonate, and terpolymers of acrylamide, N-vinyl-2-pyrrolidone, and sodium 2-acrylamido-2-methylpropane sulfonate. The ratio of the monomers in the above-described polymers is not critical; provided however, that at least 5 mole % of acrylamide or methacrylamide is present in the above-described polymers.
Particularly preferred are homopolymers of acrylamide, copolymers of acrylamide and sodium acrylate, copolymers of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, copolymers of acrylamide and N-vinyl-2-pyrrolidone, and a terpolymers of N-vinyl-2-pyrrolidone, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate. However, other polymers with more subunits may also be utilized in the practice of this invention. Additionally, within the scope of this invention is the use of combinations of homopolymers, copolymers, terpolymers, and tetrapolymers utilizing the above listed monomers.
The water soluble acrylamide-containing polymer is present in the composition in the amount of from about 0.05 to about 10 weight percent, preferably from about 0.1 to about 5 weight percent, and most preferably from 0.2 to 4 weight percent. The concentration of polymer in the composition depends to some degree upon the molecular weight of the polymer. A high molecular weight results in a higher viscosity of the resulting gel for a particular concentration of polymer.
Water generally makes up the rest of the inventive composition.
Any suitable method can be employed for preparing the composition of the invention. Thus, any suitable mixing technique or order of addition of the components of the composition to each other can be employed. However, it is generally preferred that the polymer be dispersed in water before contacting the polymer with the other components. The mixing order can vary with the type of polymer used.
The use of gelled polymers to alter the water permeability of underground formations is well known to those skilled in the art. Generally, an aqueous solution containing the polymer and a crosslinking agent is pumped into the formation so that it can diffuse into the more water permeable portions of the formation and alter that water permeability by gelling therein.
The present invention can be used in a similar manner. An aqueous solution containing the water soluble acrylamide-containing polymer, aldehyde compound, and aromatic compound can be pumped into the formation so that it alters the water permeability of the formation in a similar manner when gelation takes place. The present invention's advantage lies in the fact that, since the gelation of the polymer is delayed, the polymer has an opportunity to travel farther into the formation and effect the water permeability of portions of the formation that would normally go untreated due to their distance from the injection site. In addition, the resulting gel exhibits improved strength.
The nature of the underground formation treated is not critical to the practice of the present invention. The composition of the present invention can be used in or can be injected into, fresh water, salt water, or brines, as well as at a temperature range of from about 70° F. to about 400° F., preferably from about 150° F. to about 350° F., and most preferably from 200° F. to 300° F.
The following specific examples are intended to illustrate the advantages of this invention, but are not intended to unduly limit this invention.
EXAMPLE I
The purpose of this example is to illustrate the gelation of a water-soluble polymer by phenol and formaldehyde and to use this example as a control.
A 0.7 percent solution of a terpolymer composed of 30 wt % of N-vinyl-2-pyrrolidone, 15 wt % of acrylamide, and 55 wt % of sodium 2-acrylamido-2-methylpropane sulfonate was prepared by mixing 11.3 ml of an inverse emulsion which contained 32.4 wt % of the active terpolymer with 500 ml of synthetic sea water. The synthetic sea water used has the following formula:
______________________________________                                    
NaHCO.sub.3          3.69    grams                                        
Na.sub.2 SO.sub.4    77.19   grams                                        
NaCl                 429.00  grams                                        
CaCl.sub.2.2H.sub.2 O                                                     
                     29.58   grams                                        
MgCl.sub.2.6H.sub.2 O                                                     
                     193.92  grams                                        
distilled H.sub.2 O q.s. to                                               
                     18      liters                                       
______________________________________                                    
 ##STR4##
An aliquot of 88% phenol (0.233 g) and 0.511 ml of 37% formaldehyde were added to 100 ml of the polymer and synthetic sea water mixture described above, to provide a concentration of 2,000 ppm each of phenol and formaldehyde. Similarly, 0.582 g of phenol and 1.278 ml of formaldehyde were added to 100 ml of the polymer and synthetic sea water mixture to generate a concentration of 5,000 ppm each of phenol and formaldehyde.
Then 20 ml samples of each solution were placed in three ampules (2.2 cm by 22.5 cm). The six ampules were sealed under nitrogen and then placed upright in compartmented aluminum boxes with relief holes and placed in ovens heated to and held at 200° F., 250° F., and 300° F. Periodically, the ampules were removed from the oven and the mechanical strength of the gels was determined behind a protective shield.
As crosslinking developed, small microgels or granules began to appear, i.e., a very slight gel formed. Continued growth of the microgels to globule occured next, referred to as slight gel. Larger gel masses next appeared, referred to as partial gel, followed by the development of stronger gels with measurable tongue lengths. The tongue lengths were measured by placing each ampule horizontally behind a shield for safety, allowing the hot gelling composition to move to its equilibrium position and then measuring the length of the tongue formed. As gelation progressed with time, stronger gels and shorter tongue lengths were developed. Additionally, when some gels syneresed, liquid content in the ampules were measured by the length of the liquid with the ampules in vertical positions. The mechanical strength is expressed mathematically as
Percent Gel Strength=(AL-TL)×100/AL
where AL equals ampule length (in centimeters), and TL equals the tongue length of the gel measured in centimeters from the point at which the gel contacts the entire circumference of the tube to the farthest point to which the gel has spread. Thus the strongest gels would have a gel strength of 100% and the weakest gels would have a gel strength of 0. The tongue length results are shown in Table I.
                                  TABLE I                                 
__________________________________________________________________________
Gelation of 0.7% Terpolymer Solution in Synthetic Seawater with           
Phenol and Formaldehyde at 200° F., 250° F. and 300° 
F.                                                                        
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.                                                     
                    250° F.  300° F.                        
(days) 2,000    5,000                                                     
                    2,000  5,000    2,000    5,000                        
__________________________________________________________________________
0.3    T        VT  19.6   14.5     13.3     15.8                         
0.9    VSG      16.6                                                      
                    13.5   12.5     5.0      1.5                          
1.0    VSG      16.6                                                      
                    14.0   13.0     4.6      1.3                          
1.1    VSG      16.5                                                      
                    14.6   13.0     5.0      1.2                          
1.8    15.6     12.5                                                      
                    10.6   11.5     3.2      1.1                          
2.1    16.0     12.5                                                      
                    12.2   7.6      2.8      2.2                          
2.8    15.2     11.2                                                      
                    9.5    9.5      2.6      1.8                          
3.1    14.8     6.8 7.7    9.3      0.9      0.8                          
4.0    11.8     5.2 7.0    4.7      2.2      1.2                          
6.9    5.5      6.5 4.3    5.0      0.9      3.0 + 0.5L                   
8.1    7.0      7.0 6.0    3.8      1.0      7.0GL + 0.5L                 
8.8    7.6      7.5 7.5    4.0      1.0      5.0GL + 0.5L                 
9.9    7.5      7.8 5.9    3.5      0.8      --                           
13.8   9.5      7.5 3.4    2.4      0.7      2.1GL + 1.0L                 
21.9   9.0      7.5 3.2    2.0      4.0      3.0GL + 1.0L                 
28.0   10.5     11.2                                                      
                    2.2    1.8      11.7GL + 0.2L                         
                                             7.5GL + 1.7L                 
35.0   11.5     10.5                                                      
                    2.6    2.0      11.5GL + 0.3L                         
                                             7.3GL + 2.0L                 
63.0   10.8     10.5                                                      
                    2.5    2.5 + 0.1L                                     
                                    9.2GL + 1.0L                          
                                             7.0GL + 2.0L                 
93.0   11.4     11.5GL                                                    
                    3.5    3.3 + 0.1L                                     
                                    9.4GL + 1.5L                          
                                             6.5GL + 4.0L                 
157.0  --       --  6.0    5.0 + 0.2L                                     
                                    8.3GL + 1.5L                          
                                             5.6GL + 2.7L                 
197.0  12.5     12.7                                                      
                    6.5    6.3 + 0.3L                                     
                                    8.8GL + 1.5L                          
                                             5.7GL + 2.7L                 
233.0  13.5     12.6                                                      
                    7.2    6.8 + 0.3L                                     
                                    9.0GL + 1.5L                          
                                             6.4GL + 4.0L                 
265.0  12.6GL   15.9GL                                                    
                    6.5    7.1 + 0.3L                                     
                                    9.3GL + 1.5L                          
                                             Terminated                   
303.0  17.0GL   12.7GL                                                    
                    9.7    7.3 + 0.3L                                     
                                    9.3GL + 1.5L                          
                                             --                           
379.0  14.4GL + 0.2L                                                      
                16.3GL                                                    
                    8.5    7.6 + 0.3L                                     
                                    10.8GL + 1.6L                         
                                             --                           
510.0  13.7GL + 0.4L                                                      
                15.6GL                                                    
                    10.3   7.9 + 0.3L                                     
                                    14.0GL + 1.8L                         
                                             --                           
562.0  17.DGL + 0.5L                                                      
                15.7GL                                                    
                    11.2   8.7 +  0.3L                                    
                                    6.9GL + 2.7L                          
                                             --                           
633.0  18.6GL + 0.4L                                                      
                15.6GL                                                    
                    12.6   9.3 + 0.4L                                     
                                    7.4GL + 2.7L                          
                                             --                           
791.0  16.6GL + 0.2L                                                      
                13.7GL                                                    
                    12.5 + 0.2L                                           
                           8.7 + 0.5L                                     
                                    7.7GL + 3.7L                          
                                             --                           
912.0  19.0GL + 0.4L                                                      
                16.6GL                                                    
                    16.2GL + 0.2L                                         
                           9.9 + 0.4L                                     
                                    6.9GL + 4.0L                          
                                             --                           
1109.0 18.7GL + 0.4L                                                      
                16.2GL                                                    
                    16.0GL + 0.3L                                         
                           10.5 + 0.4L                                    
                                    7.0GL + 4.0L                          
                                             --                           
1289.0 18.6GL + 0.4L                                                      
                16.5GL                                                    
                    14.7GL + 0.3L                                         
                           11.4 + 0.3L                                    
                                    Terminated                            
                                             --                           
1535.0 18.2GL + 0.4L                                                      
                15.3GL                                                    
                    14.1GL + 0.4L                                         
                           12.8GL + 0.4L                                  
                                    --       --                           
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very Thick, VSG = Very Slight Gel.                       
 GL = Gel Length, L = the height of liquid separated from the gel, measure
 when ampule was at vertical position.                                    
Table I shows that after 1535 days at 200° F. in the presence of 2,000 ppm each of phenol and formaldehyde, relatively poor gel (based on the gel length of 18.2 cm and the liquid height of 0.4 cm) developed. The higher the liquid, the more syneresis was. Syneresis is an undesirable characteristics. Similarly, at 5,000 ppm concentration each of phenol and formaldehyde, faster gelation occurred and shorter gels were formed.
Table I also shows that, at higher temperature (250° F.) and at a given crosslinker concentration (2,000 ppm), the gelation rate increased resulting in decreased tongue length indicating improved gel strength. However, when the temperature was 300° F., excessive syneresis was observed in as short as 63 days (1.0 cm liquid) and then at 1109 days, the gel gave 4.0 cm of liquid indicating a severe syneresis.
EXAMPLE II
This example demonstrates that replacing formaldehyde with an aldehyde precursor, hexamethylenetetramine (HMTA), resulted in comparable gelation.
The runs were carried out the same as those described in Example I with the exception that HMTA was used in place of formaldehyde in the composition. The results are shown in Table II.
                                  TABLE II                                
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
Phenol and Hexamethylenetetranine at 200° F., 250° F. and   
300° F.                                                            
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F. 250° F.  300° F.                      
(days) 2,000   5,000  2,000   5,000   2,000   5,000                       
__________________________________________________________________________
0.3    T       VT     PG      21.8    22.1    23.0                        
0.9    VSG     PG     13.5    6.5     13.2    5.7                         
1.0    VSG     21.6   13.5    8.0     14.0    Terminated                  
1.1    VSG     20.4   13.0    5.2     13.8    --                          
1.8    PG      20.0   12.4    5.5     11.2    --                          
2.1    15.2    19.1   11.4    5.8     9.7     --                          
2.8    18.0    18.2   6.7     6.0     9.7     --                          
3.1    18.0    19.4   11.0    5.8     9.5     --                          
4.0    14.7    10.0   7.6     6.0     9.6     --                          
6.9    8.0     6.5    9.8     7.5     9.8     --                          
8.1    8.0     5.8    7.4     6.1     8.9     --                          
8.8    13.8    5.8    9.8     7.0     7.0     --                          
9.9    10.5    6.2    9.0     7.6     7.4     --                          
13.8   14.5    8.5    8.5     5.0     7.0     --                          
21.9   8.3     9.8    8.0     4.5     6.0     --                          
28.0   14.2    10.0   5.2     4.5     4.7     --                          
35.0   11.0    10.0   7.0     3.3     8.5     --                          
63.0   10.5    10.5   8.0     3.0     4.0     --                          
93.0   9.3     14.5   6.2 + 0.2L                                          
                              3.4 + 0.1L                                  
                                      14.0GL + 0.8L                       
                                              --                          
157.0  --      --     12.3    2.0      9.7GL + 2.1L                       
                                              --                          
197.0  5.9     5.4    4.5 + 0.3L                                          
                              1.7     12.5GL + 2.5L                       
                                              --                          
233.0  7.2     3.8    8.6 + 0.8L                                          
                              2.9      7.5GL + 3.7L                       
                                              --                          
265.0  7.7     11.0   9.3 + 0.8L                                          
                              4.5     10.6GL + 3.6L                       
                                              --                          
303.0  4.3     7.8    11.5 + 0.9L                                         
                              2.8     Terminated                          
                                              --                          
379.0  17.0GL  11.0   10.6GL + 1.1L                                       
                              3.9     --      --                          
510.0  11.2GL + 1.5L                                                      
               7.8 + 0.3L                                                 
                      10.5GL + 1.1L                                       
                              4.0 + 0.3L                                  
                                      --      --                          
562.0  12.5GL + 1.5L                                                      
               8.9 + 0.5L                                                 
                      11.3GL + 1.1L                                       
                              4.4 + 0.4L                                  
                                      --      --                          
633.0  14.1GL + 1.7L                                                      
               9.4 + 0.4L                                                 
                      11.1GL + 1.1L                                       
                              3.7 + 0.3L                                  
                                      --      --                          
791.0  12.7GL + 1.5L                                                      
               7.5 + 0.3L                                                 
                      11.0GT + 1.0L                                       
                              5.2 + 0.2L                                  
                                      --      --                          
912.0  13.5GL + 1.7L                                                      
               10.3 + 0.5L                                                
                      14.0GL + 1.1L                                       
                              5.5 + 0.3L                                  
                                      --      --                          
1109.0 12.9GL + 2.2L                                                      
               9.9 + 0.6L                                                 
                      11.1GL + 1.4L                                       
                              5.8 + 0.4L                                  
                                      --      --                          
1289.0 12.7GL + 1.9L                                                      
               9.5 + 0.5L                                                 
                      13.5GL + 1.2L                                       
                              12.4GL + 0.3L                               
                                      --      --                          
1535.0 11.9GL + 1.9L                                                      
               9.4 + 0.6L                                                 
                      11.3GL + 1.8L                                       
                              12.2GL + 0.2L                               
                                      --      --                          
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very Thick, VSG = Very Slight Gel, PG = Partial Gel.     
 GL = Gel Length, L = the height of liquid separated from the gel, measure
 when ampule was at vertical position.                                    
Table II shows that the gels produced with HMTA and phenol as crosslinkers are very comparable in quality to those made with phenol-formaldehyde crosslinking system at equal concentrations and temperatures.
EXAMPLE III
This example demonstrates that the invention composition comprising HMTA and methyl ρ-hydroxybenzoate produced superior gels to those made with phenol and formaldehyde or with phenol and HMTA as crosslinkers.
The runs were carried out the same as those described in Example I except that the crosslinking agents were methyl ρ-hydroxybenzoate and HMTA and that 3,500 ppm instead of 5,000 ppm concentration of crosslinkers was tested. The test results are shown in Table III.
                                  TABLE III                               
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
Methyl p-Hydroxybenzoate and Hexamethylenetetramine                       
at 200° F., 250° F. and 300° F.                      
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.                                                     
               250° F.                                             
                         300° F.                                   
(days) 2,000                                                              
           3,500                                                          
               2,000                                                      
                    3,500                                                 
                         2,000 3,500                                      
__________________________________________________________________________
0.2    T   T   T    T    VSG   VSG                                        
0.9    T   T   VSG-SG                                                     
                    VSG-SG                                                
                         PG    SG                                         
1.0    T   VT  S-PG S-PG PG    SG                                         
1.2    T   VT  S-PG S-PG PG    SG                                         
3.9    VSG SG  SG   SG   PG    S-PG                                       
6.9    SG  S-PG                                                           
               SG   S-PG PG    19.8                                       
11.9   S-PG                                                               
           PG  S-PG S-PG 16.9  11.2                                       
18.1   PG  21.0                                                           
               PG   PG   16.5  3.9                                        
21.9   PG  20.0                                                           
               PG   PG   VSG   12.4                                       
29.0   PG  16.8                                                           
               PG   16.0 VSG   11.4GL                                     
61.0   16.1                                                               
           11.1                                                           
               5.2  2.5  VSG   15.0GL + 1.0L                              
71.0   16.0                                                               
           11.1                                                           
               4.0  2.3  VSG   15.0GL + 1.7L                              
89.0   15.9                                                               
           13.2                                                           
               2.2  1.4  VSG-SG                                           
                               19.0GL + 1.0L                              
110.0  16.4                                                               
           15.2                                                           
               2.2  1.1  VSG   12.0GL + 1.0L                              
120.0  16.4                                                               
           15.1                                                           
               2.5  1.6  VSG   14.1GL + 1.5L                              
155.0  16.2                                                               
           15.4                                                           
               2.5  2.3  VSG    8.8GL + 1.5L                              
279.0  13.0                                                               
           8.5 3.5  0.0  NG    11.0GL + 1.5L                              
383.0  12.7                                                               
           7.3 4.7  3.4  Thin  16.5GL + 2.01                              
550.0  7.9 4.0 4.7  5.6  Thin  11.5GL + 2.0L                              
775.0  2.1 1.8 4.4  2.6  Terminated                                       
                               Terminated                                 
1022.0 2.7 1.8 3.2  2.6  --    --                                         
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VSG = Very Slight Gel, SG = Slight Gel, S-PG = Slight to      
 Partial Gel, PG = Partial Gel, GL = Gel Length, L = the height of liquid 
 separated from the gel, measured when ampule was at vertical position.   
The results shown in Table III show that substantially stronger (i.e. shorter tongue lengths) gels were obtained, when compared with the results of Table I or II. Table III also shows that the composition containing 2,000 ppm each of methyl p-hydroxybenzoate and hexamethylenetetramine did not form strong (short tongue length) gels until after aging for over 550 days at 200° F. or over 71 days at 250° F. However, the results show that some syneresis occurred at 300° F. The results in Table III further demonstrate that HMTA and methyl p-hydroxybenzoate are effective crosslinking agents suitable for high temperature application to form strong gels and to delay gelling.
EXAMPLE IV
This example shows that excellent gels are formed by a composition containing an acrylamide-containing polymer, phenyl acetate and formaldehyde.
The runs were carried out the same as those described in Example I except that phenyl acetate was used in place of phenol and that only one concentration (1,000 ppm) of each crosslinker was used. the results are shown in Table IV.
              TABLE IV                                                    
______________________________________                                    
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
1,000 ppm each of Phenyl Acetate and Formaldehyde                         
at 200° F., 250° F. and 300° F.                      
           Tongue Length or Gel Length (GL)                               
Aging Time in Centimeters                                                 
(days)     200° F.                                                 
                       250°F.                                      
                               300° F.                             
______________________________________                                    
0.2        T           T       T                                          
0.9        T           T       T                                          
1.2        T           T       T                                          
1.9        T           T       T                                          
4.9        T           T       2.4                                        
6.2        T           T       1.1                                        
9.1        T           T       0.4                                        
15.1       T           S-PG    0.6                                        
20.1       T           3.1     0.5                                        
37.0       T           0.0     0.8                                        
47.0       T           0.0     0.9                                        
54.0       T           0.0     0.8                                        
98.0       Thin        0.0     0.8                                        
210.0      1.7         0.0     0.7                                        
279.0      3.5         0.0     1.0                                        
481.0      5.5         0.0     4.2 + 0.3L                                 
706.0      10.0GL      0.0     --                                         
950.0       9.7GL      0.0     --                                         
______________________________________                                    
 T = Thick, SG-PG = Slight to Partial Gel, GL = Gel Length, L = the height
 of liquid separate from gel, measured when ampule was at vertical        
 position.                                                                
Again, Table IV shows that strong gels were formed with the inventive composition, even at very low (1,000 ppm) concentration of crosslinkers. For example, a 100% gel (i.e. 0.0 tongue length) was formed after over 20 days of aging at 250° F.
EXAMPLE V
This example illustrates an inventive gelable composition comprising an acrylamide-containing terpolymer, salicylic acid and HMTA forms strong gels.
The runs were carried out the same as Example III except that methyl p-hydroxybenzoate was replaced by salicylic acid. The results shown in Table V again demonstrate that the inventive composition containing 2,000 ppm each of crosslinkers delayed gelling until after the composition was aged for over 31 days, and a very strong gel (0.7 tongue length) was formed after over 157 days at 250° F.
                                  TABLE V                                 
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
Salicylic Acid and Hexamethylenetetramine                                 
at 200° F., 250° F. and 300° F.                      
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
        Tongue Length or Gel Length (GL) in Centimeters                   
Aging Time                                                                
        200° F.                                                    
                   250° F.                                         
                          300° F.                                  
(days)  2,000                                                             
           3,500   2,000                                                  
                      3,500                                               
                          2,000 3,500                                     
__________________________________________________________________________
0.3     T  T       T  T   T     T                                         
0.8     T  T       T  T   T     VT                                        
1.0     T  T       T  T   T     VT                                        
1.2     T  T       T  T   T     VT                                        
1.8     T  T       T  T   T     VT                                        
2.2     T  T       T  T   VSG   VSG                                       
2.8     T  T       T  T   VSG-SG                                          
                                VSG-SG                                    
3.1     T  T       T  T   S-PG  S-PG                                      
5.9     T  T       T  T   6.6   12.0                                      
8.9     T  T       T  T   4.5   4.5                                       
13.8    T  T       T  T   3.9   1.7                                       
16.9    T  T       T  T   3.5   1.8                                       
23.9    T  T       T  T   10.8  2.5                                       
31.0    Thin                                                              
           T       T  VSG 11.0  2.8                                       
62.0    Thin                                                              
           T       6.2                                                    
                      18.7                                                
                          6.8   4.7                                       
91.0    Thin                                                              
           T       2.9                                                    
                      12.2                                                
                          12.8  3.4                                       
112.0   Thin                                                              
           T       2.3                                                    
                      6.3 12.8  3.6                                       
122.0   Thin                                                              
           T       2.1                                                    
                      4.0 13.6  3.5                                       
157.0   T  VT      1.5                                                    
                      3.6 14.8  3.5                                       
281.0   NG VT      0.7                                                    
                      2.0 19.0GL                                          
                                9.5                                       
384.0   NG VT      0.6                                                    
                      2.3 BG    6.5                                       
582.0   VSG                                                               
           VT      0.6                                                    
                      1.9 BG    11.5                                      
770.0   11.5                                                              
           14.5    0.5                                                    
                      2.1 Terminated                                      
                                11.5                                      
1024.0   6.0                                                              
           14.1 + 0.3L                                                    
                   0.5                                                    
                      2.2       12.2                                      
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very Thick, VSG = Very Slight Gel, BG = Broken Gel, S-PG 
 Slight to Partial Gel, VSG-SG = Very Slight Gel to Slight Gel, GL = Gel  
 Length, L = the height of liquid separated from the gel, measured when   
 ampule was at vertical position.                                         
Again, the results shown in Table V demonstrate that gelation of the polymer was delayed and strong gels were formed, even at 300° F. (3,500 ppm concentration).
EXAMPLES VI-X
These examples further illustrate inventive gelable composition comprising an acrylamide-containing terpolymer and proper crosslinking compounds also form strong gels.
The runs were carried out the same as those described in Example I except that the crosslinkers and their concentrations in Example I were replaced by those shown in Tables VI-X. As shown in Tables VI-X, some of the inventive compositions did not gel until after the compositions had been aged at high temperatures for months and eventually formed strong (short tongue length) gels, especially those comprising phenyl acetate and HMTA (Table VIII), and phenyl salicylate and HMTA (Table X), at 250° F., formed gels having 0 cm tongue length.
                                  TABLE VI                                
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
Aspirin and Hexamethylenetetramine                                        
at 200° F., 250° F. and 300° F.                      
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.                                                     
                 250° F.                                           
                        300° F.                                    
(days) 2,000  3,500                                                       
                 2,000                                                    
                     3,500                                                
                        2,000  3,500                                      
__________________________________________________________________________
0.2    T      T  T   T  T      T                                          
0.8    T      T  T   T  T      T                                          
1.0    T      T  T   T  T      T                                          
1.2    T      T  T   T  T      T                                          
3.2    T      T  T   VT T      T                                          
3.8    T      T  T   VT T      VSG                                        
4.8    T      T  T   T  S-PG   S-PG                                       
7.9    T      T  T   T  VSG    VSG                                        
15.0   T      T  T   T  VSG    VSG                                        
47.0   T      T  18.0                                                     
                     PG VSG    VSG                                        
57.0   T      T  13.6                                                     
                     16.5                                                 
                        VSG    VSG                                        
75.0   Thin   Thin                                                        
                 5.6 6.9                                                  
                        VSG-SG 5.5GL + 5.0L                               
96.0   Thin   Thin                                                        
                 4.0 4.4                                                  
                        VSG-SG 4.6GL + 5.6L                               
106.0  Thin   Thin                                                        
                 3.4 3.2                                                  
                        VSG-SG 5.5GL + 5.0L                               
141.0  Thin   Thin                                                        
                 3.4 2.6                                                  
                        VSG-SG 4.9GL + 5.0L                               
369.0  Thin   NG 2.3 1.9                                                  
                        Thin   3.3GL + 5.2L                               
536.0  Thin   S-PG                                                        
                 1.7 1.7                                                  
                        Thin   2.9GL + 5.3L                               
762.0  Thin   13.2                                                        
                 2.2 2.3                                                  
                        Terminated                                        
                               2.5GL + 4.5L                               
1008.0 Terminated                                                         
               5.3                                                        
                 1.5 1.7                                                  
                        --     2.4GL + 4.5L                               
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very Thick, VSG = Very Slight Gel, S-PG = Slight to      
 Partial Gel, NG = No Gel, PG = Partial Gel, L = the height of liquid     
 separated from the gel, measured when ampule was at vertical position.   
              TABLE VII                                                   
______________________________________                                    
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
1,000 ppm each of Phenyl Salicylate and Formaldehyde                      
at 200° F., 250° F. and 300° F.                      
Aging Time  Tongue Length in Centimeters                                  
(days)      200° F.                                                
                        250°F.                                     
                                300° F.                            
______________________________________                                    
0.2         NG          NG      NG                                        
0.8         NG          NG      NG                                        
1.0         NG          NG      NG                                        
1.2         T           NG      NG                                        
1.9         T           NG      NG                                        
2.9         T           NG      SG                                        
3.2         T           NG      PG                                        
6.0         T           NG      4.5                                       
10.0        T           NG      3.1                                       
17.0        T           S-PG    2.5                                       
24.0        T           15.2    2.6                                       
29.0        T           8.7     2.5                                       
42.0        NG          5.5     4.9                                       
55.0        NG          4.8     10.6                                      
83.0        NG          3.2     15.1                                      
146.0       VSG         2.6     *                                         
261.0       PG          2.6     --                                        
324.0       17.9        2.8     --                                        
367.0       17.1        2.9     --                                        
416.0       16.5        2.9     --                                        
574.0       14.2        3.3     --                                        
680.0       12.3        3.3     --                                        
1070.0      13.7        5.6     --                                        
______________________________________                                    
 T = Thick, NG = No Gel, VSG = Very Slight Gel, S-PG = Slight to Partial  
 Gel, PG = Partial Gel.                                                   
 *Ampule was broken accidentally.                                         
                                  TABLE VIII                              
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
Phenyl Acetate and Hexamethylenetetramine                                 
at 200° F., 250° F. and 300° F.                      
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.  250° F.                                     
                             300° F.                               
(days) 2,000   3,500   2,000                                              
                          3,500                                           
                             2,000 3,500                                  
__________________________________________________________________________
0.2    NG      T       T  T  VSG   VSG                                    
0.9    T       T       T  T  VSG   VSG                                    
1.2    T       T       VSG                                                
                          VSG                                             
                             VSG   VSG                                    
3.9    VSG     VT      VSG                                                
                          T  VSG   S-PG                                   
7.9    VSG     VSG     VSG                                                
                          T  VSG   7.2                                    
11.2   VSG     VSG     VSG                                                
                          T  S-PG  5.2                                    
15.0   VSG-SG  VSG     VSG                                                
                          T  S-PG  4.0                                    
18.9   VSG-SG  VSG     VSG                                                
                          VSG                                             
                             PG    3.0                                    
77.0   S-PG    S-PG    PG 1.7                                             
                             6.9   2.0                                    
127.0  S-PG    PG + 0.5L                                                  
                       3.8                                                
                          0.0                                             
                             7.5   0.0                                    
153.0  PG      PG + 0.8L                                                  
                       2.8                                                
                          0.0                                             
                             15.8  3.5                                    
197.0  PG      13.5GL + 1.1L                                              
                       1.8                                                
                          0.2                                             
                             17.5GL                                       
                                   3.2                                    
246.0  PG      12.9GL + 1.8L                                              
                       1.8                                                
                          0.2                                             
                             17.5GL                                       
                                   3.8                                    
298.0  12.0GL +  2.3L                                                     
               13.1GL + 1.5L                                              
                       1.3                                                
                          0.0                                             
                             PG    4.6                                    
405.0  14.0GL + 1.8L                                                      
               11.7GL + 1.8L                                              
                       1.5                                                
                          0.0                                             
                             SG    11.5                                   
510.0  14.0GL + 2.1L                                                      
               10.7GL + 1.6L                                              
                       1.2                                                
                          0.0                                             
                             Terminated                                   
                                   13.0 + 0.2L                            
677.0  14.0GL + 2.2L                                                      
                3.5GL + 1.8L                                              
                       1.7                                                
                          0.0                                             
                             --    PG                                     
898.0  11.1GL + 2.1L                                                      
               2.9     2.5                                                
                          0.0                                             
                             --    BG                                     
1142.0 6.1 + 2.1L                                                         
               2.6     3.1                                                
                          0.0                                             
                             --    Terminated                             
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very Thick, VSG = Very Slight Gel, S-P = Slight to Partia
 Gel, PG = Partial Gel, BG = Broken Gel, GL = Gel Length, L = the height o
 liquid separated from the gel, measured when ampule was at vertical      
 position.                                                                
                                  TABLE IX                                
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
4-Aminosalicylic Acid and Hexamethylenetetramine at                       
at 200° F., 250° F. and 300° F.                      
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.                                                     
             250° F. 300° F.                                
(days) 2,000                                                              
          3,500                                                           
             2,000    3,500 2,000 3,500                                   
__________________________________________________________________________
0.2    6.9                                                                
          13.2                                                            
             4.7      4.0   5.6   5.1                                     
0.8    3.9                                                                
          3.6                                                             
             6.0      4.9   8.1   8.0                                     
1.2    4.0                                                                
          3.8                                                             
             5.0      5.1   7.5   7.8                                     
2.0    4.0                                                                
          3.6                                                             
             6.0      5.8   13.5  8.5                                     
4.9    4.o                                                                
          3.7                                                             
             6.8      6.4   10.8  12.9                                    
5.9    4.7                                                                
          4.4                                                             
             6.8      10.3  12.3  5.2                                     
12.0   3.8                                                                
          6.0                                                             
             6.5      10.6  14.4  12.1                                    
19.0   4.2                                                                
          4.0                                                             
             6.7      7.3   14.9  13.2                                    
47.0   6.3                                                                
          5.7                                                             
             11.1     7.5   PG    PG                                      
75.0   5.2                                                                
          9.4                                                             
             8.4      7.2   PG + 3.7L                                     
                                  PG + 3.5L                               
138.0  6.5                                                                
          8.8                                                             
             10.8     6.3   --    --                                      
239.0  4.2                                                                
          3.7                                                             
             5.7      7.3   Terminated                                    
                                  Terminated                              
316.0  4.8                                                                
          3.4                                                             
             8.7      4.7   --    --                                      
359.0  4.3                                                                
          3.9                                                             
             12.5     4.8   --    --                                      
391.0  4.4                                                                
          7.8                                                             
             7.8GL + 1.0L                                                 
                      7.3   --    --                                      
408.0  6.4                                                                
          7.9                                                             
             10.7GL + 1.6L                                                
                      7.2   --    --                                      
566.0  4.2                                                                
          6.7                                                             
             6.8GL + 2.1L                                                 
                      8.7 + 0.1L                                          
                            --    --                                      
672.0  4.4                                                                
          4.0                                                             
             6.7GL + 2.2L                                                 
                      9.0 + 0.1L                                          
                            --    --                                      
884.0  6.1                                                                
          7.7                                                             
             6.8GL + 2.3L                                                 
                      2.6 + 0.1L                                          
                            --    --                                      
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 PG = Partial Gel, L = the height of liquid separated from the gel,       
 measured when ampule was at vertical position.                           
                                  TABLE X                                 
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
Phenyl Salicylate and Hexamethylenetetramine                              
at 200° F., 250° F. and 300° F.                      
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.                                                     
                    250° F.                                        
                           300° F.                                 
(days) 2,000  3,500 2,000                                                 
                        3,500                                             
                           2,000  3,500                                   
__________________________________________________________________________
0.2    NG     NG    NG  NG NG     NG                                      
0.9    NG     NG    NG  NG VSG    VSG                                     
1.1    NG     NG    NG  NG VSG    VSG                                     
1.9    NG     NG    NG  NG VSG-SG VSG-SG                                  
4.9    T      T     NG  NG 7.7    7.8                                     
8.9    T      VSG   T   T  4.5    4.1                                     
12.2   T      VSG   T   T  4.o    3.4                                     
16.0   T      VSG   NG  NG 3.5    1.7                                     
19.9   T      VSG   NG  NG 3.0    0.9                                     
77.0   T      VSG   4.8 2.7                                               
                           10.1   1.9                                     
128.0  VSG    VSG   1.9 0.0                                               
                           3.6    0.0                                     
162.0  VSG    VSG   1.4 0.0                                               
                           11.1   4.5                                     
198.0  VSG    VSG   1.3 0.3                                               
                           11.1   1.8                                     
247.0  VSG-SG S-PG  1.1 0.4                                               
                           12.2   2.2                                     
299.0  VSG-SG S-PG  0.6 0.0                                               
                           12.9   2.1                                     
406.0  NG     NG    0.6 0.0                                               
                           15.8   2.1                                     
511.0  SG     S-PG  1.0 0.0                                               
                           PG     3.3                                     
678.0  SG     S-PG  0.9 0.0                                               
                           BG     3.6 + 0.4L                              
899.0  SG     SG    1.1 0.0                                               
                           Terminated                                     
                                  8.9 + 0.4L                              
1142.0 Terminated                                                         
              Terminated                                                  
                    1.5 0.0                                               
                           Terminated                                     
                                  9.5                                     
__________________________________________________________________________
 *The number given represent the approximate concentration of each        
 crosslinker.                                                             
 T = Thick, VT = Very Thick, NG = No Gel, VSG = Very Slight Gel, VSG--SG =
 Very Slight Gel to Slight Gel, BG = Broken Gel, S-PG = Slight to Partial 
 Gel, PG = Partial Gel, L = the height of liquid separated from the gel,  
 measured when ampule was at vertical position.                           
EXAMPLE XI
This example illustrates that glyoxal, a formaldehyde precursor that release formaldehyde upon heating, is not a suitable crosslinking agent.
The runs were carried out the same as those described in Example I except that glyoxal was used in place of formaldehyde. The results shown in Table XI below indicate that little nor no gels were formed. It is concluded that an aldehyde precursor that generates formaldehyde in-situ is not necessary a crosslinking agent.
                                  TABLE XI                                
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with                    
Phenol and Glyoxal at 200° F., 250° F. and 300° F.   
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length or Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.                                                     
                    250° F.                                        
                                300° F.                            
(days) 2,000 3,500  2,000 3,500 2,000 3,500                               
__________________________________________________________________________
0.2    VT    VT     T     T     T     T                                   
0.9    T     VT     T     T     NG    NG                                  
1.1    T     T      T     T     NG    NG                                  
1.3    T     T      T     T     NG    NG                                  
4.0    T     T      T     VSG   NG    NG                                  
6.0    T     T      NG    VSG   NG    NG                                  
8.0    T     T      NG    VSG   NG    NG                                  
12.0   T     T      NG    VSG   NG    NG                                  
15.0   T     VT     NG    VSG   NG    NG                                  
19.0   T     T      NG    VSG   NG    NG                                  
32.0   NG    NG     NG    VSG   NG    NG                                  
50.0   NG    NG     NG    VSG   NG    NG                                  
99.0   NG    VSG    NG    VSG   NG    NG                                  
203.0  Terminated                                                         
             S-PG   Terminated                                            
                          VSG   Terminated                                
                                      Terminated                          
277.0  --    S-PG   --    VSG   --    --                                  
323.0  --    PG + 0.5L                                                    
                    --    Terminated                                      
                                --    --                                  
372.0  --    PG + 0.3L                                                    
                    --    --    --    --                                  
424.0  --    PG + 0.3L                                                    
                    --    --    --    --                                  
530.0  --    PG + 0.3L                                                    
                    --    --    --    --                                  
635.0  --    PG + 0.2L                                                    
                    --    --    --    --                                  
862.0  --    PG + 0.2L                                                    
                    --    --    --    --                                  
1033.0 --    PG + 0.2L                                                    
                    --    --    --    --                                  
1267.0 --    S-PG + 0.2L                                                  
                    --    --    --    --                                  
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very Thick, NG = No Gel, VSG = Very Slight Gel, PG =     
 Partial Gel, S-PG = Slight to Partial Gel.                               
 L = the height of liquid separated from the gel, measured when ampule was
 at vertical position.                                                    
EXAMPLE XII
This example further demonstrates that 1,3,5-trioxane, another formaldehyde precursor which generates formaldehyde upon heating, produces gels with measurable tongue lengths only after a long period of time.
The runs were carried out the same as those described in Example XI except that 1,3,5-trioxane was used in place of glyoxal. The results presented in Table XII below show that, using phenol and trioxane as crosslinkers, gels with measurable tongue lengths did not appear until after over 6 months of aging at 250° F., either at 2,000 ppm or 5,000 ppm. The system did not produce any gel at 200° F. in the period shown in the Table, but this system might have limited application at 250° F. This system was not tested at 300° F.
              TABLE XII                                                   
______________________________________                                    
Gelation of 0.7% Terpolymer In Synthetic Seawater with                    
Phenol and 1,3,5-Trioxane at 200° F. and 250° F.            
Temp                                                                      
X-linker  Tongue Length or Gel Length (GL)                                
Conc* (ppm)                                                               
          in Centimeters                                                  
Aging Time                                                                
          200° F.    250° F.                                
(days)    2,000      5,000      2,000  5,000                              
______________________________________                                    
0.05      NG         NG         NG     NG                                 
0.10      NG         NG         NG     NG                                 
0.18      NG         T          NG     NG                                 
0.26      NG         T          NG     NG                                 
1.2       NG         T          NG     NG                                 
2.9       NG         T          NG     NG                                 
4.1       NG         NG         NG     NG                                 
5.3       NG         NG         NG     NG                                 
10.9      NG         T          NG     NG                                 
19.2      NG         NG         NG     NG                                 
34.0      NG         T          NG     NG                                 
52.0      NG         NG         NG     NG                                 
199.0     NG         NG         S-PG   PG                                 
259.0     NG         NG         17.0GL 15.3                               
433.0     NG         NG         2.2    7.2                                
664.0     Terminated Terminated 2.3    7.8                                
______________________________________                                    
 T = Thick, NG = No Gel, PG = Partial Gel, S-PG = slight to Partial Gel.  
 GL = Gel Length, L = the height of liquid separated from the gel, measure
 when ampule was at vertical position.                                    
EXAMPLES XIII-XVI
These examples show that glyoxal, when used with phenyl acetate which is a hidden phenolic disclosed in U.S. Pat. No. 4,926,943 as well as with other crosslinking agent, did not form satisfactory gels.
The runs were carried out the same as those described in Example XI except that phenyl acetate, a hidden phenolic disclosed in U.S. Pat. No. 4,926,943, as well as other crosslinking agents noted in Tables XIII-XVI, was used in place of phenol. The results shown in Table XIII indicate that after aging for 950 days, no satisfactory gels were produced under the conditions shown in Table XIII. Similar to the results presented in Table XIII, the results shown in Tables XIV-XVI clearly indicate that glyoxal is not a satisfactory aldehyde precursor for use in a gelling mixture.
              TABLE XIII                                                  
______________________________________                                    
Gelation of 0.7% Terpolymer in Synthetic Seawater with Phenyl             
Acetate and Glyoxal at 200° F., 250° F. and 300° F.  
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
         Tongue Length in Centimeters                                     
Aging Time                                                                
         200° F.                                                   
                     250° F.                                       
                                  300° F.                          
(days)   2,000   3,500   2,000 3,500  2,000 3,500                         
______________________________________                                    
0.2      T       VT      T     T      T     T                             
0.9      T       VT      T     VT     T     VSG                           
1.2      T       VT      T     VSG    T     VSG                           
1.9      T       VT      Thin  VSG    Thin  VSG                           
4.9      T       VT      T     VSG    Thin  VSG                           
6.2      T       VT      Thin  VSG    Thin  VSG                           
9.1      T       VT      Thin  SG     Thin  VSG                           
15.1     T       VT      Thin  VSG-SG T     VSG                           
20.1     T       VSG     Thin  VSG-SG T     T                             
37.0     T       S-PG    Thin  S-PG   T     T                             
47.0     T       S-PG    Thin  S-PG   Thin  T                             
54.0     T       S-PG    Thin  S-PG   Thin  Thin                          
210.0    NG      T       NG    NG     NG    NG                            
279.0    NG      S-PG    Thin  NSG    Thin  Thin                          
481.0    VSG     S-PG    Thin  Thin   Thin  Thin                          
706.0    VSG     SG      Thin  Thin   Thin  Thin                          
950.0    VSG     SG      Thin  Thin   Thin  Thin                          
______________________________________                                    
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very thick, VSG = Very Slight Gel, NG = No Gel, S-PC =   
 Slight to Partial Gel.                                                   
              TABLE XIV                                                   
______________________________________                                    
Gelation of 0.7% Terpolymer in Synthetic Seawater with Salicylic          
Acid and Glyoxel at 200° F., 250° F. and 300° F.     
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
          Tongue Length in Centimeters                                    
Aging Time                                                                
          200° F.                                                  
                       250° F.                                     
                                  300° F.                          
(days)    2,000  3,500     2,000                                          
                                3,500 2,000                               
                                           3,500                          
______________________________________                                    
0.2       T      T         T    T     T    T                              
0.9       T      T         T    T     T    T                              
1.2       T      T         T    T     T    T                              
1.9       T      T         T    VSG   Thin T                              
2.2       T      T         T    VSG   Thin T                              
3.2       T      T         Thin VSG   Thin T                              
3.9       T      T         T    VSG   Thin VSG                            
9.2       T      T         Thin VSG   Thin T                              
15.1      T      VT        Thin VSG   Thin T                              
32.0      T      VSG       Thin VSG   Thin T                              
42.0      T      VSG       Thin VSG   Thin T                              
49.0      T      VSG-SG    Thin VSG   Thin T                              
205.0     NG     T         NG   NG    NG   NG                             
274.0     NG     VSG       Thin Thin  Thin Thin                           
476.0     NG     VSG       Thin Thin  Thin Thin                           
711.0     NG     VSG       Thin Thin  Thin Thin                           
______________________________________                                    
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very thick, VSG = Very Slight Gel, NG = No Gel, VSG-SG = 
 Very Slight Gel to Slight Gel.                                           
              TABLE XV                                                    
______________________________________                                    
Gelation of 0.7% Terpolyner In Synthetic Seawater with                    
Aspirin and Glyoxal at 200° F., 250° F. and 300° F.  
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
         Tongue Length in Centimeters                                     
Aging Time                                                                
         200° F.                                                   
                      250° F.                                      
                                   300° F.                         
(days)   2,000   3,500    2,000 3,500  2,000                              
                                            3,500                         
______________________________________                                    
0.2      T       T        T     T      T    T                             
0.9      T       T        T     T      T    VSG                           
1.0      T       T        T     T      T    vsc                           
1.2      T       T        T     T      T    vsc                           
2.9      T       T        T     VSG    T    VSG                           
3.9      T       T        T     VSG    T    VSG                           
5.9      T       T        T     VSG    T    VSG                           
12.1     T       VT       T     VSG    T    T                             
28.9     T       VT       T     VSG    Thin T                             
39.0     T       VSG      Thin  VSG-SG Thin T                             
46.0     T       VSG-SG   T     VSG-SG Thin T                             
271.0    VSG     S-PG     Thick Thick  Thin Thin                          
473.0    Thick   SG       Thin  Thin   Thin Thin                          
944.0    VSG     VSG-SG   Thin  Thin   Thin Thin                          
______________________________________                                    
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very thick, VSG = Very Slight Gel, VSG-SG = Very Slight  
 Gel to Slight Gel, SG = Slight Gel, S-PG = Slight to Partial Gel.        
              TABLE XVI                                                   
______________________________________                                    
Gelation of 0.7% Terpolymer In Synthetic Seawater with Methyl             
P-Hydroxybenzoate and Glyoxal at 200° F., 250° F. and       
300° F.                                                            
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
          Tongue Length in Centimeters                                    
Aging Time                                                                
          200° F.                                                  
                     250° F.                                       
                                  300° F.                          
(days)    2,000  3,500   2,000                                            
                              3,500   2,000                               
                                           3,500                          
______________________________________                                    
0.2       VT     VT      T    T       T    T                              
0.9       VT     VT      T    T       Thin Thin                           
1.2       VT     VT      T    T       Thin VSG                            
3.9       VT     VT      T    VSG     Thin VSG                            
4.9       T      VT      VSG  VSG     Thin VSG                            
7.9       T      T       Thin VSG     Thin VSG                            
11.1      T      T       Thin VSG-SG  Thin T                              
13.1      T      T       Thin PG      Thin Thin                           
15.1      T      T       Thin VSG     Thin Thin                           
26.0      T      VSG     T    VSG-SG  Thin Thin                           
43.0      T      SG      T    SG      Thin Thin                           
53.0      T      SG      T    SG      Thin Thin                           
60.0      T      SG      T    VSG-SG  Thin Thin                           
104.0     T      VSG     T    --      --   --                             
285.0     VSG    SG      Thin VSG     Thin Thin                           
487.0     VSG    SG      Thin VSG     Thin Thin                           
722.0     VSG    SG      Thin Thin    Thin Thin                           
958.0     --     S-PG    --   Thin    --   --                             
______________________________________                                    
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very thick, PG = Partial Gel, SG = Slight Gel, VSG = Very
 Slight Gel, S-PG = Slight to Partial Gel.                                
EXAMPLE XVII
This example demonstrates that the invention composition comprising hexamethylenetetramine forms satisfactory gels.
The runs were carried out the same as those described in Example XIII except that hexamethylenetetramine was used in place of glyoxal. The results are shown in Table XVII which demonstrates that excellent gels were formed.
                                  TABLE XVII                              
__________________________________________________________________________
Gelation of 0.7% Terpolymer in Synthetic Seawater with Phenyl             
Acetate and Nexamethylenotatramine at 200° F., 250° F. and  
300° F.                                                            
Temp                                                                      
X-linker                                                                  
Conc* (ppm)                                                               
       Tongue Length of Gel Length (GL) in Centimeters                    
Aging Time                                                                
       200° F.  250° F.                                     
                             300° F.                               
(days) 2,000   3,500   2,000                                              
                          3,500                                           
                             2,000                                        
                                 3,500                                    
__________________________________________________________________________
0.2    NG      T       T  T  VSG VSG                                      
0.9    T       T       T  T  VSG VSG                                      
1.2    T       T       VSG                                                
                          VSG                                             
                             VSG VSG                                      
3.9    VSG     VT      VSG                                                
                          T  VSG S-PG                                     
7.9    VSG     VSG     VSG                                                
                          T  VSG 7.2                                      
11.2   VSG     VSG     VSG                                                
                          T  S-PG                                         
                                 5.2                                      
15.0   VSG-SG  VSG     VSG                                                
                          T  S-PG                                         
                                 4.0                                      
18.9   VSG-SG  VSG     VSG                                                
                          VSG                                             
                             PG  3.0                                      
77.0   S-PG    S-PG    PG 1.7                                             
                             6.9 2.0                                      
127.0  S-PG    PG + 0.5L                                                  
                       3.8                                                
                          0.0                                             
                             7.5 0.0                                      
153.0  PG      PG + 0.8L                                                  
                       2.8                                                
                          0.0                                             
                             15.8                                         
                                 3.S                                      
197.0  PG      13.5GL + 0.1L                                              
                       1.8                                                
                          0.2                                             
                             17.5GL                                       
                                 3.2                                      
246.0  PC      12.9GL + 1.8L                                              
                       1.8                                                
                          0.2                                             
                             17.5GL                                       
                                 3.8                                      
298.0  12.0GL +  2.3L                                                     
               13.1GL + 1.5L                                              
                       1.3                                                
                          0.0                                             
                             PG  4.6                                      
405.0  14.0GL + 1.8L                                                      
               11.7GL + 1.8L                                              
                       1.5                                                
                          0.0                                             
                             SG  11.5                                     
510    14.0GL + 2.1L                                                      
               10.7GL + 1.6L                                              
                       1.2                                                
                          0.0                                             
                             --  13.0 + 0.2L                              
677    14.0GL + 2.2L                                                      
               6.5GL + 1.82                                               
                       1.7                                                
                          0.0                                             
                             --  PG                                       
898    11.1GL + 2.0L                                                      
               2.9     2.5                                                
                          0.0                                             
                             --  GL + Water                               
1142    6.1GL + 2.0L                                                      
               2.6     3.1                                                
                          0.0                                             
                             --  --                                       
__________________________________________________________________________
 *The numbers given represent the concentration of each crosslinker.      
 T = Thick, VT = Very thick, VSG = Very Slight Gel, NG = No Gel, S-PG =   
 Slight to Partial Gel, PG = Partial Gel, GL = Gel Length, L = the height 
 of liquid separate from the gel.                                         
Although wishing not to be bound by theory, hexamethylenetetramine is probably converted to formaldehyde and ammonia upon heating. The in-situ produced formaldehyde is then coupled with a crosslinking agent to form gels with an acrylamide-containing polymer. However, glyoxal or trioxane, which is also converted to formaldehyde upon heating, does not form suitable gels with a crosslinking agent and an acrylamide-containing polymer (Tables XI and XIII-XVI). The strong and stable gels formed by hexamethylenetetramine and phenol (Table II) as well as by hexamethylenetetramine and other crosslinking agents (Tables III, V, VI, VIII, IX, X, and XVII), therefore, represent unexpected and surprising results.
The results shown in the above examples clearly demonstrate that the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned as well as those inherent therein. While modifications may be made by those skilled in the art, such modifications are encompassed within the spirit of the present invention as defined by the specification and the claims.

Claims (34)

That which is claimed is:
1. A composition comprising: (1) a water dispersible crosslinking compound selected from the group consisting of p-aminosalicylic acid, RArOC(O)R' and HOArC(O)OR", and combinations thereof; wherein Ar represents a phenyl group which can be non-substituted or substituted; R is hydrogen or a carboxylic group; R' is a C1 -C6 alkyl; R" is hydrogen, a phenyl group, or a C1 -C6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) hexamethylenetetramine; (3) a water soluble acrylamide-containing polymer; and (4) water.
2. A composition according to claim 1 wherein said crosslinking compound is selected from the group consisting of p-aminosalicylic acid, phenyl acetate, phenyl propionate, phenyl butyrate, salicylic acid, phenyl salicylate, p-hydroxybenzoic acid, methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, hexyl p-hydroxybenzoate, methyl o-hydroxybenzoate, and mixtures thereof.
3. A composition according to claim 2 wherein said crosslinking compound is phenyl acetate.
4. A composition according to claim 2 wherein said crosslinking compound is phenyl salicylate.
5. A composition according to claim 2 wherein said crosslinking compound is methyl p-hydroxybenzoate.
6. A composition according to claim 1 wherein said crosslinking compound is present in the composition in the range of from about 0.005 to about 5.0 weight %.
7. A composition according to claim 6 wherein said crosslinking compound is present in the composition in the range of from about 0.01 to about 2.0 weight %.
8. A composition according to claim 7 wherein said crosslinking compound is present in the composition in the range of from 0.03 to 1.0 weight %.
9. A composition according to claim 1 wherein said hexamethylenetetramine is present in the composition in the range of from about 0.005 to about 5.0 weight %.
10. A composition according to claim 9 wherein said hexamethylenetetramine is present in the composition in the range of from about 0.01 to about 2.0 weight %.
11. A composition according to claim 10 wherein said hexamethylenetetramine is present in the composition in the range of from 0.03 to 1.0 weight %.
12. A composition according to claim 1 wherein said polymer contains from 100 mole % to 5 mole % of a monomer selected from those monomers represented by the following formula: ##STR5## wherein R1, R2, and R3 are independently selected from the group consisting of hydrogen and alkyl groups containing from 1 to 3 carbon atoms; and contains from 0 mole % to 95 mole % of a monomer selected from the group consisting of (a) those monomers which can be represented by the following formula: ##STR6## wherein R4 is selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 6 carbon atoms, R5 is selected from the group consisting of alkylene radicals containing from 1 to 6 carbon atoms and arylene radicals containing from 6 to 10 carbon atoms, and M is selected from the group consisting of hydrogen, ammonium potassium, and sodium; and (b) those monomers represented by the following formula: ##STR7## where R6, R7, and R8 are independently selected from the group consisting of hydrogen and alkyl radicals containing from 1 to 2 carbon atoms; and (c) a monomer selected from the group consisting of acrylic acid, sodium acrylate, potassium acrylate, ammonium acrylate, methacrylic acid, sodium methacrylate, potassium methacrylate, ammonium methacrylate, N,N-dimethylacrylamide, vinylsulfonic acid, sodium vinylsulfonate, potassium vinylsulfonate, ammonium vinylsulfonate, vinylbenzylsulfonic acid, sodium vinylbenzylsulfonate, potassium vinylbenzylsulfonate, ammonium vinylbenzylsulfonate, vinylacetate, acrylonitrile, methyl acrylonitrile, vinyl alkyl ether, vinyl chloride, maleic anhydride, vinyl substituted cationic quaternary ammonium compounds, (acryloyloxyethyl)dimethylmethylammonium methyl sulfate, and sodium acrylate; and (d) mixtures thereof.
13. A composition according to claim 12 wherein said polymer is selected from the group consisting of homopolymers of acrylamide, homopolymers of methacrylamide, copolymers of acrylamide and N-vinyl-2-pyrrolidone, copolymers of acrylamide and N,N-dimethylacrylamide, copolymers of acrylamide and methacrylamide, copolymers of acrylamide and acrylic acid, copolymers of acrylamide and sodium acrylate, copolymers of acrylamide and potassium acrylate, copolymers of methacrylamide and acrylic acid, copolymers of acrylamide and N-vinyl-2-pyrrolidone, copolymers of acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, terpolymers of N-vinyl-2-pyrrolidone, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, and terpolymers of acrylamide, N,N-dimethylacrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, and combinations thereof.
14. A composition according to claim 13 wherein said polymer is a terpolymer of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropanesulfonate.
15. A composition according to claim 1 wherein said polymer is present in the composition in the range of from about 0.05 to about 10 weight %.
16. A composition according to claim 15 wherein said range is from about 0.1 to about 5 weight %.
17. A composition according to claim 16 wherein said range is from 0.2 to 4 weight %.
18. A composition according to claim 1 wherein: said crosslinking compound is selected from the group consisting of p-aminosalicylic acid, phenyl acetate, phenyl propionate, phenyl butyrate, salicylic acid, phenyl salicylate, p-hydroxybenzoic acid, methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, hexyl p-hydroxybenzoate, methyl o-hydroxybenzoate, and mixtures thereof; and said polymer is selected from the group consisting of homopolymers of acrylamide, homopolymers of methacrylamide, copolymers of acrylamide and N-vinyl-2-pyrrolidone, copolymers of acrylamide and N,N-dimethylacrylamide, copolymers of acrylamide and methacrylamide, copolymers of acrylamide and acrylic acid, copolymers of acrylamide and sodium acrylate, copolymers of acrylamide and potassium acrylate, copolymers of methacrylamide and acrylic acid, terpolymers of N-vinyl-2-pyrrolidone, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, and terpolymers of N,N-dimethylacrylamide, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate, and combinations thereof.
19. A composition according to claim 18 wherein said crosslinking compound is phenyl acetate and said polymer is a terpolymer of N-vinyl-2-pyrrolidone, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate.
20. A composition according to claim 18 wherein said crosslinking compound is methyl p-hydroxybenzoate and said polymer is a terpolymer of N-vinyl-2-pyrrolidone, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate.
21. A composition according to claim 18 wherein said crosslinking compound is salicylic acid and said polymer is a terpolymer of N-vinyl-2-pyrrolidone, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate.
22. A composition according to claim 18 wherein said crosslinking compound is phenyl salicylate and said polymer is a terpolymer of N-vinyl-2-pyrrolidone, acrylamide and sodium 2-acrylamido-2-methylpropane sulfonate.
23. A composition according to claim 1 wherein said crosslinking compound is present in the composition in the range of from about 0.005 to about 5.0 weight %; said hexamethylenetetramine is present in the composition in the range of from about 0.005 to about 5.0 weight %; said polymer is present in the composition in the range of from about 0.05 to about 10 weight %; and said water makes up the rest of said composition
24. A composition according to claim 23 wherein said crosslinking compound is present in the composition in the range of about 0.01 to about 2.0 weight percent; said hexamethylenetetramine is present in the composition in the range of about 0.01 to about 2.0 weight percent; said polymer is present in the composition in the amount of about 0.1 to about 5 weight %; and said water makes up the rest of the composition.
25. A composition according to claim 24 wherein said crosslinking compound is present in the composition in the range of from 0.03 to 1.0 weight %; said hexamethylenetetramine is present in the composition in the range of from 0.03 to 1.0 weight %; said polymer is present in the composition in the range of from 0.2 to 4 weight %; and said water makes up the rest of the composition.
26. A composition according to claim 1 wherein said composition comprises: (1) from 0.03 to 1.0 weight % of methyl p-hydroxybenzoate; (2) from 0.03 to 1.0 weight % of hexamethylenetetramine; (3) from 0.2 to 4 weight % of a terpolymer of monomers consisting of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropane sulfonate wherein said monomers are provided in a 30:15:55 weight %, respectively; and (4) from 94 to 99.7 weight % of water; wherein said weight % is based on total weight of said composition.
27. A composition according to claim 1 wherein said composition comprises: (1) from 0.03 to 1.0 weight % of phenyl acetate; (2) from 0.03 to 1.0 weight % of hexamethylenetetramine; (3) from 0.2 to 4 weight % of a terpolymer of monomers consisting of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropane sulfonate wherein said monomers are provided in a 30:15:55 weight %, respectively; and (4) from 94 to 99.7 weight % of water; wherein said weight % is based on total weight of said composition.
28. A composition according to claim 1 wherein said composition comprises: (1) from 0.03 to 1.0 weight % of salicylic acid; (2) from 0.03 to 1.0 weight % of hexamethylenetetramine; (3) from 0.2 to 4 weight % of a terpolymer of monomers consisting of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropane sulfonate wherein said monomers are provided in a 30:15:55 weight %, respectively; and (4) from 94 to 99.7 weight % of water; wherein said weight % is based on total weight of said composition.
29. A composition according to claim 1 wherein said composition comprises: (1) from 0.03 to 1.0 weight % of phenyl salicylate; (2) from 0.03 to 1.0 weight % of hexamethylenetetramine; (3) from 0.2 to 4 weight % of a terpolymer of monomers consisting of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropane sulfonate wherein said monomers are provided in a 30:15:55 weight %, respectively; and (4) from 94 to 99.7 weight % of water; wherein said weight % is based on total weight of said composition.
30. A process for reducing the permeability of watered-out or oil-depleted zones in a high temperature subterranean formation comprising injecting a composition into said formation which forms a gel in said formation wherein said composition comprises: (1) a water dispersible crosslinking compound selected from the group consisting of p-aminosalicylic acid, RArOC(O)R' and HOArC(O)OR" wherein Ar represents a phenyl group which can be non-substituted or substituted; R is hydrogen or a carboxylic group; R' is a C1 -C6 alkyl; R" is hydrogen, a phenyl group, or a C1 -C6 alkyl; and when R is a carboxylic group, R and C(O)OR" can be at ortho, meta, or para position with respect to the OC(O)R' group and the OH group, respectively; (2) hexamethylenetetramine; (3) a water soluble acrylamide-containing polymer; and (4) water.
31. A process according to claim 30 wherein said composition comprises: (1) from 0.03 to 1.0 weight % of methyl p-hydroxybenzoate; (2) from 0.03 to 1.0 weight % of hexamethylenetetramine; (3) from 0.2 to 4 weight % of a terpolymer of monomers consisting of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropane sulfonate wherein said monomers are provided in a 30:15:55 weight %, respectively; and (4) from 94 to 99.7 weight % of water; wherein said weight % is based on total weight % said composition.
32. A process according to claim 30 wherein said composition comprises: (1) from 0.03 to 1.0 weight % of phenyl acetate; (2) from 0.03 to 1.0 weight % of hexamethylenetetramine; (3) from 0.2 to 4 weight % of a terpolymer of monomers consisting of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropane sulfonate wherein said monomers are provided in a 30:15:55 weight %, respectively; and (4) from 94 to 99.7 weight % of water; wherein said weight % is based on total weight % said composition.
33. A process according to claim 30 wherein said composition comprises: (1) from 0.03 to 1.0 weight % of phenyl salicylate; (2) from 0.03 to 1.0 weight % of hexamethylenetetramine; (3) from 0.2 to 4 weight % of a terpolymer of monomers consisting of N-vinyl-2-pyrrolidone, acrylamide, and sodium 2-acrylamido-2-methylpropane sulfonate wherein said monomers are provided in a 30:15:55 weight %, respectively; and (4) from 94 to 99.7 weight % of water; wherein said weight % is based on total weight % said composition.
34. A process according to claim 31 wherein said injecting is carried out in a subterranean formation at a temperature range of from about 150° F. to about 350° F.
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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5486312A (en) * 1992-08-31 1996-01-23 Union Oil Company Of California High temperature stable gels
US5762141A (en) * 1992-08-31 1998-06-09 Union Oil Company Of California Ultra-high temperature stable gels
US6133369A (en) * 1997-04-24 2000-10-17 Stockhausen Gmbh & Co. Kc Printable swelling paste and the use thereof
US6391937B1 (en) 1998-11-25 2002-05-21 Motorola, Inc. Polyacrylamide hydrogels and hydrogel arrays made from polyacrylamide reactive prepolymers
US20080223596A1 (en) * 2007-03-14 2008-09-18 Ryan Ezell Aqueous-Based Insulating Fluids and Related Methods
US20080224087A1 (en) * 2007-03-14 2008-09-18 Ezell Ryan G Aqueous-Based Insulating Fluids and Related Methods
US20100234252A1 (en) * 2009-03-12 2010-09-16 Conocophillips Company Crosslinked swellable polymer
WO2011161581A1 (en) * 2010-06-23 2011-12-29 Schlumberger Canada Limited High temperature polymer gels for well treatments and their use
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US20130324443A1 (en) * 2010-10-25 2013-12-05 Isp Investments Inc. Salt-tolerant, thermally-stable rheology modifiers
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US9868892B2 (en) 2012-10-24 2018-01-16 Baker Hughes, A Ge Company, Llc Method of forming fluid impermeable plug in a subterranean formation
US20190106616A1 (en) * 2016-04-08 2019-04-11 Schlumberger Technology Corporation Polymer gel for water control applications
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Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795376A (en) * 1970-08-17 1974-03-05 Monsanto Co N parachute fabric
US4009755A (en) * 1976-03-17 1977-03-01 Union Oil Company Of California Selectively controlling the flow of fluids through subterranean formations
US4069869A (en) * 1977-02-11 1978-01-24 Union Oil Company Of California Plugging high permeability zones of reservoirs having heterogeneous permeability
US4147211A (en) * 1976-07-15 1979-04-03 Union Oil Company Of California Enhanced oil recovery process utilizing a plurality of wells
US4167500A (en) * 1976-06-14 1979-09-11 Lord Corporation Aqueous compositions comprising phenolic resin and crosslinking agent
US4440228A (en) * 1980-08-06 1984-04-03 Phillips Petroleum Company Gelled compositions and well treating
US4476033A (en) * 1982-07-30 1984-10-09 Phillips Petroleum Company Method and compositions for acidizing and fracturing wells
US4644020A (en) * 1983-01-28 1987-02-17 Phillips Petroleum Company Production of high molecular weight vinyl lactam polymers and copolymers
US4663367A (en) * 1984-08-30 1987-05-05 The Borden Company Limited Compositions and methods for reducing the permeability of underground strata
JPS62197402A (en) * 1986-02-25 1987-09-01 Dai Ichi Kogyo Seiyaku Co Ltd Preparation of stable water-retentive gel
US4799548A (en) * 1987-01-23 1989-01-24 Phillips Petroleum Company Gelable compositions and use thereof in steam treatment of wells
US4822842A (en) * 1987-02-03 1989-04-18 Phillips Petroleum Company Delaying the gelation of water soluble polymers
US4907656A (en) * 1988-12-30 1990-03-13 Mobil Oil Corporation Method for preventing steam channelling into a non-aquifer bottom water zone
US4926943A (en) * 1989-03-10 1990-05-22 Mobil Oil Corporation Phenolic and naphtholic ester crosslinked polymeric gels for permeability profile control
US4934456A (en) * 1989-03-29 1990-06-19 Phillips Petroleum Company Method for altering high temperature subterranean formation permeability
US4940091A (en) * 1989-01-03 1990-07-10 Mobil Oil Corporation Method for selectively plugging a zone having varying permeabilities with a temperature activated gel
US4974677A (en) * 1989-10-16 1990-12-04 Mobil Oil Corporation Profile control process for use under high temperature reservoir conditions
US5043364A (en) * 1990-03-15 1991-08-27 Phillips Petroleum Company Gelation of acrylamide-containing polymers with furfuryl alcohol and water dispersible aldehydes
US5179136A (en) * 1990-09-10 1993-01-12 Phillips Petroleum Company Gelatin of acrylamide-containing polymers with aminobenzoic acid compounds and water dispersible aldehydes

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0280283B1 (en) * 1987-02-27 1991-09-25 Talleres Daumar S.A. Automatic weighing machine
SE0101852D0 (en) * 2001-05-23 2001-05-23 Svenska Rymdaktiebolaget Method of preparing granules
DE10320763A1 (en) * 2003-05-09 2005-02-24 Azo Verwaltungs-Gmbh Device for allocating flowable material components
EP2447967B1 (en) * 2010-10-29 2015-12-23 Robert Bosch GmbH Improvements in or relating to electrically-powered garden apparatus

Patent Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795376A (en) * 1970-08-17 1974-03-05 Monsanto Co N parachute fabric
US4009755A (en) * 1976-03-17 1977-03-01 Union Oil Company Of California Selectively controlling the flow of fluids through subterranean formations
US4167500A (en) * 1976-06-14 1979-09-11 Lord Corporation Aqueous compositions comprising phenolic resin and crosslinking agent
US4147211A (en) * 1976-07-15 1979-04-03 Union Oil Company Of California Enhanced oil recovery process utilizing a plurality of wells
US4069869A (en) * 1977-02-11 1978-01-24 Union Oil Company Of California Plugging high permeability zones of reservoirs having heterogeneous permeability
US4440228A (en) * 1980-08-06 1984-04-03 Phillips Petroleum Company Gelled compositions and well treating
US4476033A (en) * 1982-07-30 1984-10-09 Phillips Petroleum Company Method and compositions for acidizing and fracturing wells
US4644020A (en) * 1983-01-28 1987-02-17 Phillips Petroleum Company Production of high molecular weight vinyl lactam polymers and copolymers
US4858693A (en) * 1984-08-30 1989-08-22 The Borden Company Limited Compositions and methods for reducing the permeability of underground strata
US4663367A (en) * 1984-08-30 1987-05-05 The Borden Company Limited Compositions and methods for reducing the permeability of underground strata
JPS62197402A (en) * 1986-02-25 1987-09-01 Dai Ichi Kogyo Seiyaku Co Ltd Preparation of stable water-retentive gel
US4799548A (en) * 1987-01-23 1989-01-24 Phillips Petroleum Company Gelable compositions and use thereof in steam treatment of wells
US4822842A (en) * 1987-02-03 1989-04-18 Phillips Petroleum Company Delaying the gelation of water soluble polymers
US4907656A (en) * 1988-12-30 1990-03-13 Mobil Oil Corporation Method for preventing steam channelling into a non-aquifer bottom water zone
US4940091A (en) * 1989-01-03 1990-07-10 Mobil Oil Corporation Method for selectively plugging a zone having varying permeabilities with a temperature activated gel
US4926943A (en) * 1989-03-10 1990-05-22 Mobil Oil Corporation Phenolic and naphtholic ester crosslinked polymeric gels for permeability profile control
US4934456A (en) * 1989-03-29 1990-06-19 Phillips Petroleum Company Method for altering high temperature subterranean formation permeability
US4994194A (en) * 1989-03-29 1991-02-19 Phillips Petroleum Company Altering high temperature subterranean formation permeability
US4974677A (en) * 1989-10-16 1990-12-04 Mobil Oil Corporation Profile control process for use under high temperature reservoir conditions
US5043364A (en) * 1990-03-15 1991-08-27 Phillips Petroleum Company Gelation of acrylamide-containing polymers with furfuryl alcohol and water dispersible aldehydes
US5179136A (en) * 1990-09-10 1993-01-12 Phillips Petroleum Company Gelatin of acrylamide-containing polymers with aminobenzoic acid compounds and water dispersible aldehydes

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5762141A (en) * 1992-08-31 1998-06-09 Union Oil Company Of California Ultra-high temperature stable gels
US5486312A (en) * 1992-08-31 1996-01-23 Union Oil Company Of California High temperature stable gels
US6133369A (en) * 1997-04-24 2000-10-17 Stockhausen Gmbh & Co. Kc Printable swelling paste and the use thereof
US6391937B1 (en) 1998-11-25 2002-05-21 Motorola, Inc. Polyacrylamide hydrogels and hydrogel arrays made from polyacrylamide reactive prepolymers
EP2628894A1 (en) 2006-09-05 2013-08-21 University Of Kansas Polyelectrolyte complexes for oil and gas applications
US20080223596A1 (en) * 2007-03-14 2008-09-18 Ryan Ezell Aqueous-Based Insulating Fluids and Related Methods
US20080224087A1 (en) * 2007-03-14 2008-09-18 Ezell Ryan G Aqueous-Based Insulating Fluids and Related Methods
US20080227665A1 (en) * 2007-03-14 2008-09-18 Ryan Ezell Aqueous-Based Insulating Fluids and Related Methods
US20100234252A1 (en) * 2009-03-12 2010-09-16 Conocophillips Company Crosslinked swellable polymer
US9139760B2 (en) 2009-03-12 2015-09-22 Conocophillips Company Crosslinked swellable polymer
US8648018B2 (en) 2009-03-12 2014-02-11 Conocophillips Company Crosslinked swellable polymer
RU2553809C2 (en) * 2009-12-11 2015-06-20 Аркема Инк. Trap for radicals in operations of oil and gas inflow intensification
US9102866B2 (en) 2009-12-11 2015-08-11 Arkema Inc. Radical trap in oil and gas stimulation operations
US9790419B2 (en) * 2010-06-23 2017-10-17 Schlumberger Technology Corporation High temperature polymer gels for well treatments and their use
US20110315382A1 (en) * 2010-06-23 2011-12-29 Hutchins Richard D High temperature polymer gels for well treatments and their use
WO2011161581A1 (en) * 2010-06-23 2011-12-29 Schlumberger Canada Limited High temperature polymer gels for well treatments and their use
CN102372818B (en) * 2010-08-23 2013-10-16 中国石油化工股份有限公司 Temperature and salt resistant copolymer for oil field and preparation method thereof
CN102372818A (en) * 2010-08-23 2012-03-14 中国石油化工股份有限公司 Temperature and salt resistant copolymer for oil field and preparation method thereof
US20130324443A1 (en) * 2010-10-25 2013-12-05 Isp Investments Inc. Salt-tolerant, thermally-stable rheology modifiers
US10023782B2 (en) 2010-10-25 2018-07-17 Isp Investments Llc Salt-tolerant, thermally-stable rheology modifiers
US9611416B2 (en) * 2010-10-25 2017-04-04 Isp Investments Llc Salt-tolerant, thermally-stable rheology modifiers
US9868892B2 (en) 2012-10-24 2018-01-16 Baker Hughes, A Ge Company, Llc Method of forming fluid impermeable plug in a subterranean formation
CN104762076A (en) * 2014-12-09 2015-07-08 西南石油大学 Water soluble AM-AA-modified nanometer SiO2 functional monomer terpolymer oil-displacement agent
CN105085836A (en) * 2014-12-09 2015-11-25 西南石油大学 Modified nanometer SiO2 graft copolymer
CN104762076B (en) * 2014-12-09 2018-01-23 西南石油大学 Water-soluble AM AA modified Nanos SiO2Function monomer terpolymer oil displacement agent
CN105085838A (en) * 2014-12-09 2015-11-25 西南石油大学 Preparation method of modified nanometer SiO2-AA-AM copolymer
US20190106616A1 (en) * 2016-04-08 2019-04-11 Schlumberger Technology Corporation Polymer gel for water control applications
US10472555B2 (en) * 2016-04-08 2019-11-12 Schlumberger Technology Corporation Polymer gel for water control applications
US11162016B2 (en) 2016-06-02 2021-11-02 The Curators Of The University Of Missouri Re-assembling polymer particle package for conformance control and fluid loss control
US11268009B2 (en) 2016-06-02 2022-03-08 The Curators Of The University Of Missouri Fiber assisted re-crosslinkable polymer gel and preformed particle gels for fluid loss and conformance control
US11549048B2 (en) 2016-06-02 2023-01-10 The Curators Of The University Of Missouri Re-assembling polymer particle package for conformance control and fluid loss control
US11214729B2 (en) 2018-08-31 2022-01-04 The Curators Of The University Of Missouri Re-crosslinking particle gel for CO2 conformance control and CO2 leakage blocking
CN111607369A (en) * 2019-02-25 2020-09-01 中国海洋石油集团有限公司 High-temperature-resistant gel plugging agent crosslinked by bisphenol propane and hexamethylenetetramine

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